seeing as the wings are strapped on I believe that is Icarus.
I never noticed that the wings were tied on until I scanned that stamp at high resolution and posted it here! I am a bit weak in my knowledge of Greek mythology and didn't know who Icarus was. The Scott catalogue lists the figure as Daedalus
who was the father of Icarus
According to the myth, Daedalus was a skillful craftsman who bult the wings to escape from Crete where he was held prisoner in a tower. Here is an excerpt from Wikipedia on Daedalus
"Daedalus set to work to fabricate wings for himself and his young son Icarus. He tied feathers together, from smallest to largest so as to form an increasing surface. The larger ones he secured with thread and the smaller with wax, and gave the whole a gentle curvature like the wings of a bird. When the work was finally done, the artist, waving his wings, found himself buoyed upward and hung suspended, poising himself on the beaten air. He next equipped his son in the same manner, and taught him how to fly. When both were prepared for flight, Daedalus warned Icarus not to fly too high, because the heat of the sun would melt the wax, nor too low because the sea foam would make the wings wet and they would no longer fly. Thus the father and son flew away.
They had passed Samos, Delos and Lebynthos when the boy began to soar upward as if to reach heaven. The blazing sun softened the wax which held the feathers together and they came off. Icarus fell into the sea. His father cried, bitterly lamenting his own arts, called the land near the place where Icarus fell into the ocean Icaria in memory of his child. Eventually Daedalus arrived safely in Sicily, in the care of King Cocalus, where he built a temple to Apollo, and hung up his wings, an offering to the god."
So indeed it is an image of an ancient flying man (Daedalus or his son Icarus) and not an angel.